9781728285810 has 128 divisors (see below), whose sum is σ = 25608409666560. Its totient is φ = 2376739123200.

The previous prime is 9781728285779. The next prime is 9781728285821. The reversal of 9781728285810 is 185828271879.

It is a super-2 number, since 2×9781728285810² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 130627780 + ... + 130702640.

It is an arithmetic number, because the mean of its divisors is an integer number (200065700520).

Almost surely, 2^{9781728285810} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 9781728285810, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12804204833280).

9781728285810 is an abundant number, since it is smaller than the sum of its proper divisors (15826681380750).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

9781728285810 is a wasteful number, since it uses less digits than its factorization.

9781728285810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79204.

The product of its (nonzero) digits is 36126720, while the sum is 66.

The spelling of 9781728285810 in words is "nine trillion, seven hundred eighty-one billion, seven hundred twenty-eight million, two hundred eighty-five thousand, eight hundred ten".